Returns the resulting (pseudo)rapidity and azimuthal coordinates when summing the momenta of a particle set.

Parameters:¶

pmu : MomentumArray¶

Momenta of the particles in the set.

pseudo : bool¶

If True, will use pseudorapidity. If False, will use true rapidity. Default is True.

Returns:¶

rapidity_centre, azimuth_centre – The central location on the (pseudo)rapidity-azimuth plane for the given particle set.

Return type:¶

float

Notes

While this does provide central coordinates, which are effectively weighted by \(p_T\), this is not mathematically equivalent to the \(p_T\)-weighted centroid, see weighted_centroid(). This function takes a sum of the underlying momenta, and gives the the coordinates of the reconstructed object. This is often more desirable, as the calculation is implicitly consistent with the detector geometry, whereas weighted_centroid() treats the (pseudo)rapidity-azimuth plane as Cartesian.